516 research outputs found

    A comparison of the effect of PVT data application methods on predicted depletion drive reservoir performance

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    It is generally agreed that the evolution of gas from oil within a reservoir is most closely approximated by the differential liberation process, while gas liberation in the flow string, surface separator, and stock tank is most nearly represented by flash liberation. To conform with this assumed physical behavior, appropriate application of both flash and differential liberation data in the computation of reservoir performance by material balance methods is indicated. In this work, simple depletion-drive oil and gas recoveries were calculated (1) using differential liberation data only, and (2) using differential liberation data adjusted to incorporate the results of flash separation tests. A comparison of the results obtained indicates that while the differences in depletion-drive recoveries so predicted may sometimes be unimportant from a practical standpoint, they can be appreciable where considerable differences exist between the flash and differential formation-volume-factors. Utilization of differential liberation data which has been converted from a “residual oil to a stock tank oil basis throughout the material-balance equations appears to be a simple, appropriate method of incorporating the effects of both liberation processes. This conversion may be accomplished by multiplying differential solubility and shrinkage values by the ratio of flash to differential bubble-point formation-volume-factor --Abstract, page 1

    Peptide Signatures for Prognostic Markers of Pancreatic Cancer by MALDI Mass Spectrometry Imaging

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    Simple Summary: Pancreatic cancer remains one of the most lethal tumor entities worldwide given its overall 5-year survival after diagnosis of 9%. Thus, further understanding of molecular changes to improve individual prognostic assessment as well as diagnostic and therapeutic advancement is crucial. The aim of this study was to investigate the feasibility of Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) to identify specific peptide signatures linked to established prognostic parameters of pancreatic cancer. In a patient cohort of 18 patients with exocrine pancreatic cancer after tumor resection, MALDI imaging analysis additional to histopathological assessment was performed. Applying this method to tissue sections of the tumors, we were able to identify discriminative peptide signatures corresponding to nine proteins for the prognostic histopathological features lymphatic vessel invasion, lymph node metastasis and angioinvasion. This demonstrates the technical feasibility of MALDI-MSI to identify peptide signatures with prognostic value through the workflows used in this study. Abstract: Despite the overall poor prognosis of pancreatic cancer there is heterogeneity in clinical courses of tumors not assessed by conventional risk stratification. This yields the need of additional markers for proper assessment of prognosis and multimodal clinical management. We provide a proof of concept study evaluating the feasibility of Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) to identify specific peptide signatures linked to prognostic parameters of pancreatic cancer. On 18 patients with exocrine pancreatic cancer after tumor resection, MALDI imaging analysis was performed additional to histopathological assessment. Principal component analysis (PCA) was used to explore discrimination of peptide signatures of prognostic histopathological features and receiver operator characteristic (ROC) to identify which specific m/z values are the most discriminative between the prognostic subgroups of patients. Out of 557 aligned m/z values discriminate peptide signatures for the prognostic histopathological features lymphatic vessel invasion (pL, 16 m/z values, eight proteins), nodal metastasis (pN, two m/z values, one protein) and angioinvasion (pV, 4 m/z values, two proteins) were identified. These results yield proof of concept that MALDI-MSI of pancreatic cancer tissue is feasible to identify peptide signatures of prognostic relevance and can augment risk assessment

    Activating WASP mutations associated with X-linked neutropenia result in enhanced actin polymerization, altered cytoskeletal responses, and genomic instability in lymphocytes

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    X-linked neutropenia (XLN) is caused by activating mutations in the Wiskott-Aldrich syndrome protein (WASP) that result in aberrant autoinhibition. Although patients with XLN appear to have only defects in myeloid lineages, we hypothesized that activating mutations of WASP are likely to affect the immune system more broadly. We generated mouse models to assess the role of activating WASP mutations associated with XLN (XLN-WASP) in lymphocytes. XLN-WASP is expressed stably in B and T cells and induces a marked increase in polymerized actin. XLN-WASP–expressing B and T cells migrate toward chemokines but fail to adhere normally. In marked contrast to WASP-deficient cells, XLN-WASP–expressing T cells proliferate normally in response to cell-surface receptor activation. However, XLN-WASP–expressing B cells fail to proliferate and secrete lower amounts of antibodies. Moreover, XLN-WASP expression in lymphocytes results in modestly increased apoptosis associated with increased genomic instability. These data indicate that there are unique requirements for the presence and activation status of WASP in B and T cells and that WASP-activating mutations interfere with lymphocyte cell survival and genomic stability

    Pathophysiology of Male Hypogonadism Associated with Endogenous Hyperestrogenism — Evidence for Dual Defects in the Gonadal Axis

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    FEMINIZING tumors of the adrenal cortex are associated with symptoms that presumably reflect the combined effects of estrogen excess and androgen deficiency — gynecomastia, diminished libido, attenuated potency, and testicular and prostatic atrophy.1 2 3 4 5 Although such tumors are extremely rare, they provide a unique opportunity to appraise the nature of endogenous estrogen action on the gonadal axis in men. In principle, the pathophysiologic effects of estrogen hypersecretion could be expressed at the level of either the Leydig cell or the hypothalamic–pituitary axis (or both), with consequent suppression of androgen production. In the present studies, we investigated the endocrine consequences of reversible endogenous estrogen excess in a patient with a surgically resectable feminizing adrenal cortical tumor

    The medical student

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    The Medical Student was published from 1888-1921 by the students of Boston University School of Medicine

    Coincident light and clock regulation of pseudoresponse regulator protein 37 (PRR37) controls photoperiodic flowering in sorghum

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    Optimal flowering time is critical to the success of modern agriculture. Sorghum is a short-day tropical species that exhibits substantial photoperiod sensitivity and delayed flowering in long days. Genotypes with reduced photoperiod sensitivity enabled sorghum's utilization as a grain crop in temperate zones worldwide. In the present study, Ma(1), the major repressor of sorghum flowering in long days, was identified as the pseudoresponse regulator protein 37 (PRR37) through positional cloning and analysis of SbPRR37 alleles that modulate flowering time in grain and energy sorghum. Several allelic variants of SbPRR37 were identified in early flowering grain sorghum germplasm that contain unique loss-of-function mutations. We show that in long days SbPRR37 activates expression of the floral inhibitor CONSTANS and represses expression of the floral activators Early Heading Date 1, FLOWERING LOCUS T, Zea mays CENTRORADIALIS 8, and floral induction. Expression of SbPRR37 is light dependent and regulated by the circadian clock, with peaks of RNA abundance in the morning and evening in long days. In short days, the evening-phase expression of SbPRR37 does not occur due to darkness, allowing sorghum to flower in this photoperiod. This study provides insight into an external coincidence mechanism of photoperiodic regulation of flowering time mediated by PRR37 in the short-day grass sorghum and identifies important alleles of SbPRR37 that are critical for the utilization of this tropical grass in temperate zone grain and bioenergy production

    Linac-LHC EP Collider Options

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    We describe various parameter scenarios for a ring-linac ep collider based on LHC and an independent electron linac. Luminosities between 103110^{31} and 1033cm2s110^{33} cm^{-2}s^{-1} can be achieved with a s.c. linac, operated either in pulsed or in cw mode, with optional recirculation, at a total electric wallplug power of order 20 MW. Higher luminosities, of several 1033cm2s110^{33} cm^{-2}s^{-1} can be reached by investing more electric power or by energy recovery. Finally, merits of a linac-ring ep collider are discussed

    Ernst Freund as Precursor of the Rational Study of Corporate Law

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    Gindis, David, Ernst Freund as Precursor of the Rational Study of Corporate Law (October 27, 2017). Journal of Institutional Economics, Forthcoming. Available at SSRN: https://ssrn.com/abstract=2905547, doi: https://dx.doi.org/10.2139/ssrn.2905547The rise of large business corporations in the late 19th century compelled many American observers to admit that the nature of the corporation had yet to be understood. Published in this context, Ernst Freund's little-known The Legal Nature of Corporations (1897) was an original attempt to come to terms with a new legal and economic reality. But it can also be described, to paraphrase Oliver Wendell Holmes, as the earliest example of the rational study of corporate law. The paper shows that Freund had the intuitions of an institutional economist, and engaged in what today would be called comparative institutional analysis. Remarkably, his argument that the corporate form secures property against insider defection and against outsiders anticipated recent work on entity shielding and capital lock-in, and can be read as an early contribution to what today would be called the theory of the firm.Peer reviewe
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